Sometimes you are so sick of arguing a point. Sometimes the other side of the debate has reduced its arguments to the adult (but equally childish) equivalent of "is not". In times like these the best thing to do is to take a deep breath and walk away. You will give yourself ulcers by forcing the issue and then you'll be even worse off because the other party still refuses to listen to anything even remotely resembling reason.
In these situations, your counterparts will cheer and jeer as you walk away. They will laugh and point and declare themselves the de facto "winners". Don't worry. Save your energy for a worthwhile debate.
So it is not always the case that SilenceImpliesConsent. Indeed, it is more important to PickYourBattles than to fall prey to ArgumentumAdInfinitum.
Sometimes even verbal consent just means that people are tired of arguing and/or can't think of a better solution. Unanimity doesn't always imply consensus: